Sharpening base



FIG. 1 is a front right top perspective view of a first embodiment of a sharpening base showing my new design;

FIG. 2 is a back left top perspective view thereof;

FIG. 3 is a front view thereof;

FIG. 4 is a back view thereof;

FIG. 5 is a left-side view thereof;

FIG. 6 is a right-side view thereof;

FIG. 7 is a top view thereof;

FIG. 8 is a bottom view thereof;

FIG. 9 is a front right top perspective view of a second embodiment of a sharpening base showing my new design;

FIG. 10 is a back left top perspective view thereof;

FIG. 11 is a front view thereof;

FIG. 12 is a back view thereof;

FIG. 13 is a left-side view thereof;

FIG. 14 is a right-side view thereof;

FIG. 15 is a top view thereof; and,

FIG. 16 is a bottom view thereof. 

CLAIM The ornamental design for a sharpening base, as shown. 